The present invention relates to fluid applicating and vehicle washing apparatus, and particularly to such apparatus which delivers a clustered spray of fluid in a repeating two dimensional pattern.
A number of fluid applicating devices have been developed, many of which are designed for washing vehicles. Many of such devices use a plurality of nozzles to deliver fluid for washing the vehicles. In most instances of vehicle washing apparatus, the nozzles and vehicles move relative to one another so that fluid from a given nozzle covers an area larger than the spray pattern of the nozzle itself. See, for example, U.S. Pat. No. 4,719,932. For the most part, however, the covered area is extended in only one direction, or, in other words, the covered area has only one dimension larger than the spray pattern of the nozzle itself. In other instances, the nozzles are made to reciprocate in one plane while the vehicle passes by in a direction perpendicular to that plane.
Zero degree nozzles are well known in the vehicle washing art. They have the advantage of providing high fluid flow rates at the vehicle surface, thus helping to remove dirt from the surface. Because the stream from a zero degree nozzle does not diverge, however, the area impacted by a single nozzle is very small. Further, when zero degree nozzles are used in reciprocating devices, especially where the vehicle passes perpendicularly past the plane of reciprocation, the washed pattern often has a "zebra" look, alternating stripes of washed and unwashed surfaces.
A recently advertised piece of car wash equipment, titled "Mr. Spinner" and sold by Northwest Hydraulic Services, Inc., Warren, Ohio, includes a spinning head with two or four zero degree nozzles mounted on 90.degree. elbows secured into the circumference of the head. Apparently the spray axis of the nozzle is slightly off angle from the axis of rotation of the head so that the diameter of the spray pattern is larger than the distance between the nozzles. As the head rotates, a circular pattern is sprayed. Apparently each nozzle is positioned off angle by the same amount, so that each nozzle sprays the same diameter circle. In one system described, three Mr. Spinner heads are mounted in a vertical line, to spray three circular patterns stacked on top of each other. Apparently the vertical stack may be arranged in an "oscillating" column, where the entire system oscillates on an axis of rotation parallel to the vertical stacking alignment. As a vehicle moves past the vertical system, either oscillating or stationary, each head sprays a horizontally extending rectangular area. Depending on the distance between heads and the spray diameter, these three areas may apparently be made to overlap to cover the entire side of the vehicle. The heads are said to rotate at 1000 rpm or more depending on water system pressure.
One disadvantage of the "Mr. Spinner" system is that multiple heads are required to cover the entire side of the vehicle. Further, the areas at the tops and bottoms of the circular pattern, especially if those patterns overlap, receive more washing fluid than the central sections. Thus either washing fluid is wasted if the vehicle speed is slow enough to assure that the central sections are cleaned, or there is unevenness of cleaning if the vehicle speed is increased.
Certain vehicles present particularly difficult washing situations. For example, many trucks have side walls which include reinforcing ribs that extend in a plane perpendicular to the surface of the side wall. Fluid sprays directed at the side wall do not clean such perpendicular surfaces. If a nozzle is pointed at a non-perpendicular angle toward the side wall, it may be able to clean one perpendicular side of the reinforcing rib, but not the opposite side. Of course, multiple nozzles could be mounted at opposing non-perpendicular angles to reach both of such perpendicular surfaces, but this requires twice the number of nozzles and associated plumbing.